Missing validation when reusing Foundry project impacts published accelerator templates (model availability, quota, and access checks)

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**Output from `azd version`**
Latest

**Describe the bug**
We have a couple of questions related to the behavior of azd when reusing an existing Foundry project, specifically around validation and access control:

1. Model Availability & Capacity Validation
Is there any built-in logic within azd to validate whether:

The required OpenAI model (e.g., gpt-4, gpt-4o, etc.) is available in the selected Foundry project?

The model has sufficient capacity or quota in the region selected for deployment?

2. Access Permissions
What is the expected behavior if a user does not have access to the selected Foundry project (e.g., missing access to the resource group or OpenAI resource)?

Does azd handle this scenario with a clear error or fallback?

`⚠️ This behavior is currently impacting published Foundry accelerator templates, where users may unknowingly deploy into inaccessible or misconfigured environments, leading to deployment failures or unclear error messages.`

Is there a recommended way to pre-check this to avoid runtime failures?
**To Reproduce**
- Use azd up and attempt to point to an existing Foundry project.
- Use a model that may not be available or lacks quota.
- Use a user account that does not have access to the project or resource group.

**Expected behavior**
- We expect azd to validate model availability and capacity before deployment.
- We expect a graceful failure or a clear error message if the user does not have access to the Foundry project or its resources.

**Environment**
Information on your environment:
* Language name and version - Python 3.11
* IDE and version : [e.g. Visual Studio 16.3] - VS Code/Codespaces

**Additional context**
This validation is important for improving the user experience when deploying accelerators using azd, especially when working with shared or centrally managed Foundry projects.